The main aim is, during the years 1992-1997, to carry forward the productive program of prospective research on key problems of cardiovascular and non-cardiovascular disease epidemiology in progress in Chicago since the late 1950s, and to take full advantage of the mass of data being accrued on cause-specific mortality among the 43,800 adults in 4 cohorts with long-term follow-up. For example, among 14,370 white women in one cohort with a current estimated 1,400 deaths and an additional 1,100 projected over the ensuing years, it will be possible to provide highly precise estimates of the impact on cause-specific mortality of multiple traits measured at baseline, as well as to compare this impact in white women with that observed among the 20,232 white men in that cohort. Similarly, with 352 current estimated deaths among 3,823 black men and women in the same cohort and a projected additional 250 deaths, meaningful black-white comparisons of mortality patterns and risk factor associations will be feasible and are to be conducted. Further, with the long-term follow-up (up to 35 years in one cohort and up to 25 in the others), and with the large numbers involved in the 4 cohorts, major factors influencing survival to older age, i.e., .longevity, can be examined with considerable precision. In-depth characterization at baseline of habitual eating patterns of men in the cohort with longest follow-up (up to 35 years by 1997) and with post-baseline re-examinations, makes possible analyses of the key question of the relation of multiple nutritional variables to other baseline variables, to long-term mortality risk, and to prognosis for longevity. In addition, with the large numbers involved, much useful information will be available not only on risk associated with high levels of several known risk factors but also on cause-specific mortality in those at the low end of distributions of such factors as body mass, cholesterol, blood pressure and traits that might explain any differential mortality patterns. Alongside these central aims, a variety of additional specific research projects will be undertaken focussed mainly on baseline traits (e.g., ECG abnormalities, glycemia, uricemia, body mass index, personality traits, alcohol and cigarette use) and long-term mortality risk; for the 2 cohorts with interim post-baseline examination, change in these traits and impact of change on mortality are to be analyzed. Special methodologic issues arising in the course of these analyses, including statistical analytical questions, are--as in the past-- to receive special attention.